git-ack: record an ackHEADmaster

This is a simple script that I use by piping
incoming mail with an ack to it.
It produces an empty ack commit suitable for
squshing with git rebase -i -autosquash.

Works best if people ack individual commits: you simply
pipe each ack to git ack, before pushing your branch,
rebase.

Some people ack series by responding to cover letter
or to commit 1.
To address this usecase, there are two additional
flags: -s saves the ack signature in a file (you can
save several in a row), -r creates an ack for
a given patch using the saved signature.
Thus: pipe ack(s) to git ack -s, then select and pipe
each individual patch to git ack -r.

If it's found useful, this script can either
become a first-class command (with documentation
and tests) or be integrated as a flag into git am.

Limitations: requires that index is clean, this is
so we can create an empty commit recording the ack.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/contrib/git-ack b/contrib/git-ack
new file mode 100755
index 0000000000..4aeb16abd9
--- /dev/null
+++ b/contrib/git-ack
@@ -0,0 +1,84 @@
+msg=`mktemp`
+patch=`mktemp`
+info=`git mailinfo $msg $patch`
+subj=`echo "$info"|sed -n 's/^Subject: //p'`
+author=`echo "$info"|sed -n 's/^Author: //p'`
+email=`echo "$info"|sed -n 's/^Email: //p'`
+auth="$author <$email>"
+date=`echo "$info"|sed -n 's/^Date: //p'`
+sign=`mktemp`
+echo "ack! $subj" > $sign
+echo "" >> $sign
+if
+    git diff --cached HEAD
+then
+    nop < /dev/null
+else
+    echo "DIFF in cache. Not acked, reset or commit!"
+    exit 1
+fi
+GIT_DIR=`pwd`/${GIT_DIR}
+
+usage () {
+	echo "Usage: git ack " \
+            "[-s|--save|-a|--append|-r|--restore |-c|--clear]\n" >& 2;
+        exit 1;
+}
+
+append=
+save=
+clear=
+
+while test $# != 0
+do
+	case "$1" in
+	-a|--append)
+		append="y"
+		;;
+	-s|--s)
+		save="y"
+		;;
+	-r|--restore)
+		restore="y"
+		;;
+	-c|--clear)
+		clear="y"
+                ;;
+	*)
+		usage ;;
+	esac
+	shift
+done
+
+if
+    test "$clear"
+then
+    rm -f "${GIT_DIR}/ACKS"
+fi
+
+if
+    test "$save"
+then
+    if
+        test "$append"
+    then
+        cat $msg >> "${GIT_DIR}/ACKS"
+    else
+        cat $msg > "${GIT_DIR}/ACKS"
+    fi
+fi
+
+if
+    test "$restore"
+then
+    msg = ${GIT_DIR}/ACKS
+fi
+
+if
+    grep '^[A-Z][A-Za-z-]*-by:' $msg >> $sign
+then
+    git commit --allow-empty -F $sign --author="$auth" --date="$date"
+else
+    echo "No signature found!"
+    exit 2
+fi